How does the rapid denaturation of delicate proteins, like those in fish, affect the texture in a pressure cooker?

They turn into a uniform, over-processed texture.

The very efficiency of the pressure cooker in breaking down tough connective tissues and starches—achieved through rapid protein denaturation at high temperatures—becomes a liability when dealing with ingredients that require gentle handling. Delicate proteins, such as those found in fish, are designed to separate into desirable flakes when cooked slowly and gently. In the intense, accelerated environment of a pressure cooker, this denaturation process happens too quickly and completely. Instead of achieving desirable flakiness, the structure breaks down excessively, resulting in a texture described as mushy or over-processed, where the food loses its distinct structural integrity.